The solution according to one or more embodiments of the present invention relates to the network field. More specifically, this solution relates to wireless network access.
Networks are commonly used to interconnect remote data-processing systems, in order to share resources and information; a typical example is the Internet, which is formed by billions of data-processing systems being connected one to another through a global communication network.
The access to the networks is more and more often implemented with wireless techniques (i.e., without any physical connection). This is manly due to the widespread diffusion of mobile stations (MB), such as smart-phones and net-books, which are commonly used to access the networks, and especially the Internet, while around; particularly, the increasing need of relying on remote services leveraging the Internet may require the capability of connecting to the Internet almost from everywhere.
The most common solution for accessing the Internet with a mobile station is of using a mobile telephone infrastructure; indeed, the mobile telephone infrastructure, especially if based on the 3rd generation (3G) technology, provides a bandwidth comparable with the one commonly provided by wired connections. However, the access to the Internet with the mobile telephone infrastructure is still quite expensive; this is particularly true abroad when it is necessary to exploit a local mobile telephone operator applying very high rates. Moreover, the mobile telephone infrastructure may be not always available with the bandwidth required to provide an acceptable level of performance.
Alternatively, it is possible to connect to a wireless network Access Point (AP)—typically based on the Wireless Fidelity (Wi-Fi) technology; the access point relays information between each mobile station connected thereto and the Internet (which the access point is connected to in a wired way). The access point may be either unprotected or protected. An unprotected access point allows accessing the Internet to whatever mobile station within the unprotected access point's transmission range (for example, in public locations); conversely, a protected access point requires some sort of authentication/registration before granting the access to the Internet (for example, to restrict the protected access point's access or to collect a payment).
However, the unprotected access points are not available everywhere; therefore, it may happen that a user needing to access the Internet is not within the transmission range of any unprotected access point. In this condition, locating any unprotected access point nearby the user may be very difficult, if not impossible (especially when the user is in an unknown location, for example, abroad).
Some techniques have been proposed in the art in an attempt to alleviate this problem.
For example, US-A-2005/0143094 (the entire disclosure of which is herein incorporated by reference) discloses an access point locator service that may be offered by a mobile telephone operator; in this case, the mobile telephone operator determines the access point being closest to each mobile station (according to the mobile station's current position) and notifies the closest access point to the mobile station (either in a push mode or in a pull mode). However, this requires a connection with the mobile telephone operator (with the same drawbacks pointed out above).
US-A-20105159818 (the entire disclosure of which is herein incorporated by reference) discloses a method wherein the mobile stations continually collect information about the unprotected access points (comprising their position as determined via a GPS system) into a shared database, which is then used to select a specific unprotected access point that is nearby each mobile station. However, this involves high energy consumption by the mobile stations (since either their Wi-Fi or GPS functions have to be on), which strongly limits a lifetime of their batteries. Moreover, this requires a large memory space in the mobile stations to store this database and a corresponding logic to query the database; moreover, the database may be not up-to-date (with the databases' update that requires an access to the Internet that may be not available when an unprotected access point is found not to work any longer).
Likewise, in US-A-2007/0167174 (the entire disclosure of which is herein incorporated by reference) the mobile stations collect information about the unprotected access points into a shared database; in this case, each mobile station sends a request for nearby unprotected access points to a provider, which selects the nearby unprotected access points from the database and returns corresponding information to the mobile station. However, as above this involves high energy consumption by the mobile stations, which strongly limits a lifetime of their batteries; moreover, this requires an access to the Internet to contact the provider, so that is does not work when this is not possible or desirable in other ways as pointed out above, or when the information about the unprotected access points cannot be downloaded in advance.
In US-A-2007/0297355 as well (the entire disclosure of which is herein incorporated by reference), the mobile stations collect information about the unprotected access points; in this case, each mobile station retrieves information about nearby unprotected access points directly from other mobile stations via a local connection. A similar technique is also disclosed in “WI-FI ACCESS POINT DISCOVERY SYSTEM FOR MOBILE USERS, Nakai, Y.; Ohshima, K.; Tajima, K.; Terada, M., Computer Science and Software Engineering (JCSSE), 2011 Eighth International Joint Conference on 11-13 May 2011, ISBN: 978-1-4577-0686-8” (the entire disclosure of which is herein incorporated by reference). However, as above this involves high energy consumption by the mobile stations, which strongly limits a lifetime of their batteries. Moreover, this technique may not work when no other mobile stations are available nearby; in any case, the information provided by the other mobile stations may be of little use when the information was collected in an area that is not of interest.